1. Field of the Invention
This invention pertains to an electrical oven for articles of food, the oven has distinct broiling, baking and toasting zones.
2. Prior Art
Hot food articles, such as pizzas, are frequently prepared at the place of consumption, and the article may be sized to constritute a single serving. It has been found that in attempting to bake such articles rapidly, there is a tendency for the baking to be uneven. This problem is heightened by the fact that the same equipment will typically be use for baking a pizza that beings in the frozen state as well as one that begins in the unfrozen state, and of course, the degree of freezing can vary from point to point on a particular pizza, thereby causing uneven rising, uneven baking and uneven browning, and in some instances even causing burning before the article is ready for consumption. There can be superficial overcooking with inadequate rising of dough. to resolve such problem in the past, a separate oven has been utilized to thaw the dough before baking, and such an arrangement becomes burdensome in that the operator needs to use two ovens, needs to have multiple opening and closing of doors, and is placed at a disadvantage in needing to estimate baking time.
A concept for solution to the foregoing heating problem in provided by the oven of U.S. Pat. No. 3,846,069. This oven has a vertical axis helical track of several levels with electric heating elements in between the track levels and a rotatable reel for advancing circular food packages down the track and over the heating elements. An important feature of U.S. Pat. No. 3,847,069 is the provision of epicyclic movement of a food package to give even heating of the food.
U.S. Pat. No. 3,847,069 discloses two configurations of heating elements, in the first there is a continual length of heating element mounted underneath a relatively wide open track from the top of the bottom of the track. A second and alternative configuration is disclosed having a top section of track without a heater and a bottom section of track with a heater, the top section in the oven of U.S. Pat. No. 3,847,069 being referred to as a warming zone and the bottom section in the oven of U.S. Pat. No. 3,847,069 being referred to as a baking zone.
The oven of U.S. Pat. No. 3,847,069 will cook a food item as described therein.
However, it has been found that this oven will not interchangeably and properly heat either of a frozen or a refrigerated but unfrozen food article. It has been found that this oven cannot apply extremely high intensity of heats and that the oven must use relatively low heat intensities and therefore take a relatively lengthy period of time per food article. This oven has alo been found to need a lengthy track and a large oven chamber which results in high cost of manufacture and a rate of heat loss through the cabinet which makes for a very high power consumption as well as requiring a high amperage power source. This oven required a continual input of power at a level sufficient to heat a food product, regardless of whether or not there was food in the oven and the heater arrangement also made no provision for varying the power output of the heater as the food load in the oven was increased or decreased or removed.
Further, the structure of the oven of U.S. Pat. No. 3,847,069 has been found prohibitively expensive for commercial usage and has been found difficult to build, to assemble, and to clean. It will be appreciated that any food oven is subject to spattering and collection of grease and cooking residue and must be cleanable and periodically cleaned in the public interest.
It is also realized that ovens of this type can no longer be inefficient users of energy and that massive applications of energy far in excess of actual workload are no longer tolerable or monetarily affordable.
It has been the past practice to slowly heat frozen or refrigerated foods in a convection oven and an oven of this type can be seen in any pizza shop and every individual who has ordered a pizza is well aware that the cooking time is in the range of 15 minutes to one half hour. This time is also required for pies and the like which are usually cooked in a person's home. The faster alternative has been a microwave oven but the food cooked by a microwave oven is usually not browned and these ovens are extremely expensive and handle only a single or a few items of food at one time and do not allow opening of the oven chamber while in operation.